Railway crossings are inherently unsafe due to weather conditions, lack of attention by vehicle operators crossing the tracks and the fallibility of railway crossing signalling devices. Various systems have heretofore been designed to minimize problems associated with detecting an oncoming train approaching a railway crossing. Such systems are described in U.S. Pat. Nos. 3,929,307; 4,120,471 and 4,723,737.
Although each of these systems improves the reliability of detecting oncoming trains at railway crossings, studies have shown that motor vehicle operators will nevertheless try to beat the train at the railway crossing, or will simply be unaware of the flashing signal at the crossing.
In some cases, railway crossings and road traffic signals present vehicle operators with information which can place the vehicle in a dangerous location with respect to the railway crossing. For example, railway crossings are often located near traffic lights at an intersection. In most cases, the traffic signals and the railway crossing signals operate independently. Although traffic and road planners make an effort to place traffic signals at a safe distance from railway crossings, this is not always possible. Unfortunately, accidents have occurred at such location, wherein either a bus or a truck overhangs the railway crossing while stopped at a red light. This may also occur when traffic is backed-up at the traffic light and the last vehicle does not completely clear the railway crossing.
In some situations, two or more tracks may cross a highway with insufficient spacing between the tracks for a bus or truck to clear both tracks.
Whether accidents are caused by the inattention of the drivers, undesirable weather conditions or inadequate traffic planning, a railway crossing collision avoidance system is required which will reduce the likelihood of a railway crossing accident. Accordingly a need exists for a railway crossing collision avoidance system which can overcome the problems associated with the aforementioned prior art.
It is therefore an object of the present invention to provide a collision avoidance system for railway crossings in which a receiver located at the railway crossing is used to receive information from an oncoming railway vehicle which is indicative of the railway vehicle's velocity and time of arrival at the crossing.
Yet another object of the present invention is to provide a collision avoidance system for railway crossings in which the railway crossing is provided with a processor which makes use of the information received from the railway vehicle to establish an alarm condition as an oncoming railway vehicle approaches the railway crossing.
Yet another object of the present invention is to provide a collision avoidance system for railway crossings in which a transmitter located at the railway crossing emits an alarm signal directed to approaching road vehicles, which is indicative of how close the rail vehicle is to the crossing.
Yet another object of the present invention is to provide a collision avoidance system for railway crossings in which the alarm signal emitted by the railway crossing provides the operator of the vehicle with various levels of alarms depending on how close the rail vehicle is to the crossing.
Yet another object of the present invention is to provide a collision avoidance system for railway crossings in which the location of crossings can either be pre-stored on the rail vehicle's processor or transmitted from each crossing as the rail vehicle approaches each crossing.